NASA is bringing better weather information to pilots and forecasters with the help of airborne sensors installed on a fleet of commuter airliners.

A team led by researchers at NASA’s Langley Research Center, Hampton, Va., designed, built and equipped dozens of Mesaba Airlines aircraft with the Tropospheric Airborne Meteorological Data Report (TAMDAR) instrument. The TAMDAR sensor allows aircraft flying below 25,000 feet to automatically sense and report atmospheric conditions. Observations are sent by satellite to a ground data center. The center processes and distributes up-to-date weather information to forecasters, pilots and those who brief pilots.

The TAMDAR instrument was developed by the Georgia Tech Research Institute, Atlanta, and AirDat, L.L.C., Morrisville, N.C., for NASA’s Aviation Safety and Security Program. The TAMDAR is compact and weighs only 1.5 pounds. The instrument measures humidity, winds, pressure, temperature, icing and turbulence with the help of location, time and altitude provided by built- in Global Positioning System technology. Large airliners fly above most weather and collect limited atmospheric data. When equipped with the TAMDAR sensor, regional aircraft, which typically fly below 25,000 feet, will provide more information to weather forecasters and the aviation community.

“The TAMDAR team has worked to develop a lightweight, affordable airborne sensor that can be used to automatically report conditions,” said Taumi Daniels, TAMDAR project leader at Langley. “Our goal is to give pilots better weather information, so they can make better decisions in flight.”

The TAMDAR team has already validated the technology in previous ground and flight tests. The Great Lakes Fleet Experiment, started in January, is assessing the performance of the sensor on 64 Mesaba SAAB 340 aircraft. Mesaba Airlines is based in Minneapolis. The experiment is testing the sensors in an operational environment for the first time and is helping determine the value of airborne observations to aviation forecasts.

Private industry, meteorologists, researchers and scientists at weather forecast offices are part of the partnership that will analyze the data. The partners include NASA; AirDat; the Federal Aviation Administration (FAA); the National Oceanic and Atmospheric Administration; the National Center for Atmospheric Research, Boulder, Colo.; Massachusetts Institute of Technology Lincoln Laboratory, Lexington, Mass.; Meteorological Service of Canada, Montreal; UK MET Office, London; and Meteorological Network of Europe, Toulouse, France.

The data the team collects could also benefit all weather forecasts and weather forecasting models, because it increases the number of observations in the lower atmosphere. There are only 90 weather balloon sites nationwide used to collect temperature, wind and moisture data from twice-daily atmospheric soundings. The Great Lakes Fleet Experiment will add 1300 more daily atmospheric soundings.

The NASA Aviation Safety and Security Program is part of NASA’s Aeronautics Research Mission Directorate. It is also in partnership with the FAA, aircraft manufacturers, airlines and the Department of Homeland Security. The program’s goal is to develop technologies to help reduce the fatal aircraft accident rate, protect air travelers and the public from security threats.

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